John Gill Commentary Genesis 44:31

"it will come to pass, when he seeth that the lad is not [with us], that he will die: and thy servants will bring down the gray hairs of thy servant our father with sorrow to Sheol." — Genesis 44:31 (ASV)

It shall come to pass, when he sees that the lad [is] not
[with us], that he will die
As soon as ever he sees us, without asking any question and observes that Benjamin is missing he will conclude at once that he is dead, which will so seize his spirits, that he will expire immediately: and your servants shall bring down the gray hairs of your servant, our
father, with sorrow to the grave ;
as he said would be the case, (Genesis 44:29); and which would be very afflicting to his sons to be the cause of it, and could not be thought of without the utmost uneasiness and distress.